Include SoftAP config in TetheringEventCallback

Include SoftApConfiguration in TetheringEventCallback via
TetheringInterface, to allow apps to know which interfaces are created
with their SoftApConfigurations.

API-Coverage-Bug: 371133403

Bug: 216524590
Test: atest TetheringTest CtsTetheringTest
Change-Id: I1b4868ba8327bee3b03c0f21e5b4f0845f2f24a8
diff --git a/Tethering/common/TetheringLib/api/system-current.txt b/Tethering/common/TetheringLib/api/system-current.txt
index 1728e16..0e85956 100644
--- a/Tethering/common/TetheringLib/api/system-current.txt
+++ b/Tethering/common/TetheringLib/api/system-current.txt
@@ -21,8 +21,10 @@
 
   public final class TetheringInterface implements android.os.Parcelable {
     ctor public TetheringInterface(int, @NonNull String);
+    ctor @FlaggedApi("com.android.net.flags.tethering_with_soft_ap_config") public TetheringInterface(int, @NonNull String, @Nullable android.net.wifi.SoftApConfiguration);
     method public int describeContents();
     method @NonNull public String getInterface();
+    method @FlaggedApi("com.android.net.flags.tethering_with_soft_ap_config") @Nullable @RequiresPermission(value=android.Manifest.permission.NETWORK_SETTINGS, conditional=true) public android.net.wifi.SoftApConfiguration getSoftApConfiguration();
     method public int getType();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.net.TetheringInterface> CREATOR;